Project Summary/Abstract This is resubmission of an application for a K08 award for Eugene Richardson, MD, PhD, an Assistant Professor of Global Health and Social Medicine at Harvard Medical School. Dr. Richardson is an infectious disease physician with doctoral training in anthropology who is establishing himself as a young investigator in clinical and social scientific research of emerging infectious diseases such as Ebola virus (EBOV). This K08 award will provide Dr. Richardson with the support necessary to accomplish the following goals: (1) to conduct clinical and social scientific investigations of Ebola virus disease in Liberia; (2) to learn to design more effective containment strategies for emerging infectious diseases by integrating rigorous ethnographic and epidemiological evidence; (3) to become an expert in the social epidemiology of emerging infectious diseases in low-income settings; and (4) to develop an independent clinical research career. Dr. Richardson has a strong background in clinical infectious diseases and anthropology. This career development award will enable him to address several remaining gaps in the training specific to his career goals. Specifically, he seeks advanced training in (1) epidemiology and (2) biostatistics and will accomplish this by completing an MPH (Quantitative Methods Field of Study) at the Harvard School of Public Health. To further achieve his training goals, Dr. Richardson has assembled a mentoring team comprised of: Primary mentors: Dr. Paul Farmer, who conducts anthropological global health research, and Dr. Ichiro Kawachi, a world renown expert in social epidemiology; Advisers: Dr. Megan Murray, an expert in infectious disease transmission dynamics, Dr. Mosoka Fallah, Deputy Director of the National Public Health Institute of Liberia (NPHIL) and Principal Investigator of the PREVAIL VI study, and Dr. Phyllis Kanki, who has decades of virology experience in West Africa. Despite over 28,000 reported cases, our understanding of the epidemiology of EBOV infection is limited, including empirical data explaining why this outbreak was so much larger than previous ones. Dr. Richardson has been invited by the NIH-PREVAIL (Partnership for Research on Ebola Virus in Liberia) team to expand his Harvard KL2 research grant into an independent study named PREVAIL IX: Social Epidemiology of Ebola Virus Disease. By engaging EVD survivors and their seropositive contacts, he will focus on defining the prevalence and distribution of undocumented EBOV infection (i.e., instances of EBOV transmission that went undetected during the 2013-16 containment response) throughout Liberia and then use these data to estimate the number of undocumented Ebola virus infections across West Africa (Aim 1). He will then couple these data with ethnographic interviews and surveys to determine the social and epidemiologic factors associated with undocumented EBOV infection (Aim 2). This research will form the basis for a longitudinal study of the impact of post-Ebola health systems strengthening on health outcomes related to infectious disease transmission dynamics (e.g., HIV, TB, Lassa, and malaria) in West Africa, to be proposed in an R01 grant application before the end of the K award.